Process of recovering condensable vapors from gas mixtures



Aug. 1o 192e. 1,595,682

G. G. OBERFELL ET A.

PROCESS OF RECOVERING CONDENSABLE VAPORS FROM GAS MIXTURES Original Filed May 20. 1919 COMPRESSOR LIQUID RECEIVER e' @mib/1cm @gw/f- Patented Aug. l0, 1926.

UNITED STATES 1,595,682 PATENT OFFICE.-

GEORGE G. OBERFELL,

0F TULSA, OKLAHOMA, ANID GEORGE A. BURRELL, OF PITTS- :BURG-H, PENNSYLVANIA, ASSIGNORS T0 GASOLINE RECOVERY CORI?ORATIIION, A

CORPORATION OF DELAWARE.

IPROCESSIOF RECOVERING CONDENSABLE VAPORS FROM GASMIXTURES.

Application led May 20, 1919, Serial No. 298,559. Renewed January 5, 1926.

dmenstruum'from which they are later separated and recovered' in liquid form by distillation or other methods, and also in the rubber industry, wher-e gasoline vapors are mixed with air after use, lost. In both of these instances, it is often a fact, that not all of the gasoline vapors are recovered.

This loss also occurs in many chemical operations where vaporsescape from gases and are entirely lost.

The object of this invention is to prevent this loss and to make possible a more complete recovery of such vapors.

It has been discovered by the applicants,

that some solid substances and particularly charcoal and silica gel are adapted for use as absorbent media for vapors, and havenot been proposed heretofore for such use, and one of the objects ofv this invention is to provide a process, in which solid substances apparatus b ma be used for this purpose.

pplicants have discovered that charcoal made from cocoanut shells, vor other nut shells, hard coal, wood, etc., and which is made from such substances by rst heating at about 1,000o C., for twelve hours, with subsequent cooling and reheating with air, steam, carbon dioxide or 4other suitable oxidizing agent, is particularly adapted for this purpose, as by this means there is produced a charcoal of exceptional absorbing qualities. l

In order that ltheinvention may beclearly understood, a drawing which shows dia ammatically a form o 'wh1ch the invention may be practiced. n this drawing, A represents a -dehydrating vapor may be removed from the gas entering the chamber. B is an absorbing chamber, adapted to contain the solid absorbing substance.

condenser C and and are usually is filed herewith f jacket B chamber in which any water B is a jacket surrounding the absorbing chamber, which may be filled with' Iwater or other agent for cooling the chamber, during the process of absorption and which may be used heating the chamber when it is desired to recover from the solid absorbent the vapors absorbed by it.

C is a condenser, in which 'the vapors passing from the chamber B are condensed as a steam jacket, for y into liquld form. D is a receivin tank for the liquid, condensed inthe cham er C. E is a pump .or compressor for compressing anyfvap'rs which are not liquefied by the which are drawn from the the tank D.

G is a second condenser, into which vapors, compressed forced, and where they are liquefied. H is a second receiving-tank, for liquefied vapors from the condenser G. I is what may be termed a stabilizing tank, which insures be used as a storage which may be circulated through the absorbing medium during distillation as" hereinafter described.` A

The operation of the process isas follows: The' gas to coverable vapors may be passed directly from the entrancepipe A10 by way of pipes A11 and a into the absorbing vessel B, which by the pump E are a constant iow -of gas and which may also tank for a second gas' be treated, carrying the re'v has been first filled with a solid absorbing substancel such as charcoal, preferably in granular form, or s1l1ca gel or other desired solid substance, or it may be first passed by way of pipesAlZand A1s through the dehydrator chamber A, where the water vapor -is removed and thence into the absorbing chamber B through the pipe a, or 1t may be first run by way of pipes A12 and A14 into the stabilizing tank I, thence through'the pipes A15 vand A13 into the dehydrator chamber and into the absorber, as desired.-

In theabsorbing chamber, the solid medium absorbs the vapors carried by the gas, and the absorption is 4aided by supplying the surrounding the vessel 'B, with a cooling medium lsuch as water or other cooling agent. l

-The gas and vapors which have not been absorbed in the chamber B, pass out of the said chamber and may be led en the absorbingl medium has reached through the .pigemK to a place of consumption.

its absorption limit, the Jfresh incoming gas i-s passed into another chamber filled with fresh absorbing material.-

In the recovery of the absorbed vapors from the solid absorbing substance the absorbing chamber B is heated, preferably byA introducing steam into the jacket B, surrounding the chamber B and the heat drives the absorbed vapors out of the absorbent material. These vapors are led by pipes b, b into the condenser C where they are cooled and condensed into liquid form in a well known manner, the liquid passing through pipes c, c into the receiving tank D.

It may happen that uncondensed vapors enter and accumulate in the tank D, in which event such vapors are pumped fromv the tank D through pipes d,rd, d2, compressed bythe pump E and forced through pipes e, e', e2 into a second condenser G from which the liquefied vapors are led to the receiving tank H by the pipe g. Any

uncondensed vapors in thetank H are led' through pipe 71. back into the pipe a, to again be sent through the absorber, or may be passed into line K by way of line K.

' Suitable valves and cocks in the pipe lines are indicated on the drawing throughout thesystem by the letter X.

` lt may be stated that the release of the absorbed vapors'from the absorbent is facilitated and expedited by applying suction to the absorbing chamber at the time of heatin the chamber.

We ave also 'discovered that some absorbed vapors may be more easily and more completely recovered by circulatmg another gas or` va or throughthe solid absorbing medium, t e release of vapors in such case 'being facilitated, if the said gas or vapor is circulated at reduced pressure, while heating the absorbing medium.

For example, air which is practically free from vapor, if circulated through the heated absorbent, will remove vapor from the absorbent. The vapors thus removed are condensed and ow into the receiving tanks. @These vapors may be more thoroughly removed Vfrom the air by passing it through a liquid absorbing medium, from which they maybe recovered if desired by distillation.

'i The air, after being wholly or partly denuded of its absorbed vapors, may be circulated repeatedly through the solid absorbent until Vthe solid absorbent is practically freed of its charge of condensable vapors. l 4We do not wish to limit ourselves to the exact details of procedure, as described and shown by the drawing, as obviously this drawingishows only one manner in which the process may be carried out. There are various ways 1n which the apparatus may be built,'to absorb vapors in and to recover them from a solid absorbent, and various changes may be made in the process itself, without departing from the spirit of our invention'. l

We have found, for instance, that the introduction of a substance like glycerine into the charcoal in the absorbing chamber at the time of heating the chamber torecover the vapors, hastens the distillation, `the glycerine entering the pores of the charcoal and driving the vapors out.

What we claim and desire tof secure by Letters Patent is l. The process of removing hydrocarbon vapors from a gas mixture and recovering them in liquid form, which c onsists in passing the gas mixture through a solid absorbent' medium consisting of activated charcoal which absorbsv the vapors, then subjecting theA solid absorbent to heat, while under a pressure, to drive the absorbed vapors out of the absorbent, then condensing a portion of the vapors driven oli', at

a relatively low temperature, then 'compressing the remaining portion of said vapors at a pressure greater than that of the atmosphere and condensing the same.

2. The process of recovering liquetiable vapors from a gas 'mixture which consists in absorbing the vapors in a solid absorbing medium consisting of activated charcoal, then removing the absorbed vapors from the medium by heating the latter and 'by circulating another gas'through the solid absorbent while heatin the same at a pressure, and then condensing the vapors in the circulating gas by cooling.

3. The process of recovering liqueable vapors from a gas mixture, which consists in absorbing the vapors 1n a solid absorblng medium. cons1st1ng` of activated charcoal, then removing the absorbed vaporsl from the medium by heating the latter and by circulating another gas through the solid absorbent while heating the same, at a pressure, then condensing a part of the vapors i-n the circulating gas by cooling, then compressing the remaining vportion of the vapors at a pressure greater than one atmosphere and then condensing the same. 4c. A process of recovering vapors of substances which are liquid under atmospheric temperature and pressure from a gas mixture, consisting in absorbing the vapoixsv in activated charcoal, distilling the absorbed vapors from the charcoal,vcondensing a ortion of the vapors distilled from'-the`c arcoal, subjecting the vapors remaining from said condensation to pressure, and subsequently condensing said compressed vapors.

In testimony whereof we aix our signatures.l

lsnorted-Mi. OBERFELL. GEORGE A. BURRELL 

